U.S. Pat. No. 4,203,769 issued May 20, 1980 to Guestaux relates to antistatic layers for photographic applications based on vanadium pentoxide. In addition to the conductive metal oxide, various polymeric binders are added to increase the mechanical durability of the antistatic layer. In particular, various cellulose derivatives are used for this purpose including cellulose acetate, cellulose acetate butyrate, methyl cellulose, cellulose acetate phthalate and cellulose etherphthalate. These cellulose derivative binders together with vanadium pentoxide form particularly stable dispersions in solvent mixtures. These solutions can be stored for long periods without the formation of precipitates of the oxide. They can also be filtered to remove large particulates without plugging the filter media with metal oxide. Both are essential for the practical use of vanadium pentoxide in manufacturing.
However, when such coating solutions are applied to cellulose acetate film supports by immersion roll coating, significant coating defects result. These coating solutions, which are stable in their own right, are unstable in the presence of the cellulose triacetate film support. As a result, precipitates of the metal oxide form in the coating bead and are then deposited as visible specks in the coating layer. Such specks are objectionable in a photographic film product.